PHARMACOLOGICAL STUDY OF BOVINE AIRWAYS - EVIDENCE FOR EXCITATORY AND INHIBITORY EFFECTS OF HISTAMINE

  • 1 January 1979
    • journal article
    • research article
    • Vol. 43  (4) , 384-391
Abstract
Bovine airway muscle contracts to carbachol > histamine > 2-methylhistamine > prostaglandin[PG]F2.alpha.. Trachea of neonatal calves are more sensitive to histamine than those of older cattle. Partially contracted bovine airways relax to PGE1 and PGE2 > dopamine > phenylephrine > 4-methylhistamine > dimaprit. Histamine-induced airway constriction was incompletely blocked by mepyramine and the mepyramine-resistant component was blocked by atropine. After H1-receptor blockade, histamine-induced tracheobronchial relaxation was incompletely antagonized by metiamide and not blocked by propranolol or indomethacin, suggesting an atypcial histamine receptor not associated with catecholamine or PG production.